Cyclic Cum Static Triaxial Test System

Introduction

The system is a highly advanced combination of hydraulic and pneumatic technology where s1 is applied through hydraulic system in dynamic tests and s2 & s3 are applied through pneumatic system. It is totally based on Close Loop principle. The processing of the pre-programmed signal and machine response signal in the P.I.D. Controller is at the speed of 10 KHz. This keeps the machine working within the limits of ± 1% of the programmed signal. Confining pressure & Back pressure are also controlled through computer and operates on close loop control mechanism.

The system is capable of performing following tests as per relevant standard ASTM/BS/AASHTO/IS etc.: Saturation, consolidation, UU, CU, CUBar, CD Triaxial tests with pore pressure and Volume change measurement, Isotropic and Anisotropic tests, Stress & Strain Path control tests, Liquefaction test, Stress Controlled Cyclic Triaxial strength of soils, Strain Controlled Cyclic Triaxial strength of soils, determination of modulus and damping properties of soils, Resilient Modulus of soils etc. (Optional- Ko consolidation tests & Bender Element tests)

Salient Features

  • Based on SERVO CONTROLLED HYDRAULIC CLOSED LOOP FEEDBACK mechanism
  • Conforming to stringent requirement as per the International norms (ASTM 3999 & ASTM 5311)
  • Fully Computer Controlled operation to control Axial Loading, Cell Pressure & Back pressure with User friendly Software
  • Stress / Strain Controlled Cycling from 0.01 Hz to 10 Hz with 128 data sets per second
  • Dynamic Loading Range ± 50N to ± 9kN (Higherloads on request)
  • Suitable for Controlled Axial Loading in Stress/Strain basis in Static Triaxial testing to conduct UC, UU, CU, CUBar, CD tests
  • Facility to study Liquefaction behavior of soil
  • Digitally controlled Pressure Controllers for applying Confining and Back Pressure Range 10kPa –1000kPa (Standard)
  • Suitable Triaxial cell to accommodate Sample Sizes up to 100mm diameter x 200mm height and a Cell pressure of 1000kPa (Standard)
  • Online Plotting of Graphs ( Load v/s Displacement, Load v/s Time, Displacement v/s Time) with real time display of data
  • Advanced Analysis Software as per ASTM 3999 & 5311 for Cyclic testing and Routine Static Triaxial testing

Load Frame

Loading Frame is free standing two pillar type unit. It has a base and a cross head with fitted actuator along with servo valve. Cross head carrying the Hydraulic Actuator for conducting dynamic tests is movable on threaded columns to adjust the height of the sample. Arrangement is also provided for locking of the crosshead at any desired position. An lectromechanical system consisting of highly precise servo motor is provided for conducting routine static tests. Static and dynamic loading would be fully computer controlled. It can accommodate Triaxial cell for sample sizes up to 100mm diameter & 200mm height.

Hydraulic Actuator for Cyclic Loading

Actuator is a linear motion device, which gives a controlled motion either on stress basis or strain basis. It is a precision piece of equipment which follows the command from the
wave generator through the servo valve. It is an equal area ram and piston with surface finish of 0.2 microns. End plates have metallic seals for side thrust. Servo valve is fixed to the actuator. These valves are high performance two stage valves with a pressure drop of @70 bars.

Technical Specifications:-

Type : Double Acting
Capacity : ±10kN
Stroke length : ± 50mm
Frequency range : 0.01Hz-10Hz
Displacement transducer : ±50mm
Operating Pressure : 100 kg/cm2
Servo Valve 2 stage : 20LPM

Note : Higher capacity Actuators upto ± 100kN can also be provided on request.

Hydraulic Power Supply

Hydraulic power supplies are compact in design and are suitable for the supply of required flow and pressure for the movement of the actuator. It has an oil tank of adequate capacity, vane type pump powered by a three phase motor. All the electrical controls including the temperature controller are fixed on one side of the tank. It includes all the accessories like pressure line filter, return line filter, oil level, relief valve, pressure gauge and suitable type air/water cooled heat exchanger. Anti vibration mountings are provided as standard along with the HPS.

Technical Specifications:-

Flow of the pump : 15LPM
Operating Pressure : 100 kg/cm²
Type of Pump : Vane
Capacity of the oil tank : 100 litres
Power rating of the motor : 5 HP
Heat Exchanger capacity : 4500 kcal/hr

System will be supplied with necessary cable and fittings for the operation of the machine. Total machine operates on 440VAC 3 phase supply.

Triaxial Cell With Accessories

Standard Triaxial Cell can accommodate sample size, ranging from 38mm to 100mm diameter with L/D ratio of 1:2. It is suitable for both Static and Dynamic tests (Compression & Extension). It has a submersible load cell connected to the transfer bar. Linear bearings ensure smooth movement of the transfer bar (plunger). Base of the cell has four no-volume change valves, one each for back pressure, pore pressure, confining pressure and top drainage. Sensors for pore pressure and back pressure are attached to the stainless steel base.

Tests Possible : Static & Dynamic (Compression/Extension or both)
Confining Pressure : Up to 1000 kPa
Specimen Size : Up to 100mm diameter & 200mm height
Submersible Load cell : ±5kN
: ±1kN, ±2kN or ±10kN (Optional)

Note : High Pressure Triaxial cell up to 2000kPa can also be supplied as per requirement.
Please specify the capacity of the Load cell along with the order)

Automatic Pressure System

HEICO Pneumatic Pressure system has two line pressure distribution systems for both Confining and Back pressure with air/water bladder system with a panel complete with pressure gauge and outlets for two pressures. Control panel is a combination of controlled Electronics and pneumatic regulators. There are two independent lines one for confining pressure and the other for back pressure.

A separate Vacuum line with vacuum regulator and gauge is also provided for de-airing of water and vacuum application. A de-airing chamber of 15 Liters is also provided. Both pressures can be set and controlled digitally through computer. A sensitive volume change sensor fitted with differential pressure transducer is fixed on one side to measure the change in volume during the test. It consists of necessary valves to measure B-value during saturation.

Confining Pressure : Up to 1000kPa
Back Pressure : Up to 1000kPa
Volume change : 80cc / 200cc
De-airing chamber : 15litres
Compressor : 1000kPa
Vacuum Pump : Creates vacuum of 70cm mercury

Note : High Pressure system (Confining and Back pressure) up to 1700kPa can also be supplied as per requirement.

Pneumatic Cyclic Cum Static Triaxial Test System (Suitable for frequencies up to 10Hz)

HS 28.630

This model is similar to HS28.610 with the exception of Pneumatic Actuator in place of Hydraulic actuator, thus making system more compact (Hydraulic Power Pack is not required) with a maximum test frequency up to 10Hz and Dynamic Loading from ±10N to ± 4kN.

The main parts of the system are:-

  • Load Frame with Pneumatic Actuator
  • Triaxial Cell with accessories
  • Automatic Pressure system with Compressor and De-airing system
  • PC based Control system and Application Soft ware
    a.  Signal Conditioning and Controlling Unit with Transducers
    b.  Computer for Controlling and Data acquisition
    c.  Control & Analysis software

Electromechanical Cyclic Triaxial Test System For Soils​

HS 28.620

Meets the essential requirements of ASTM-311/3999
This Model is similar to HS28.610 with the exception of Electromechanical Actuator in place of Hydraulic Actuator for dynamic loading, thus making the system more compact and less noisy (Hydraulic Power pack is not required) with maximum test frequency up to 5Hz with peak to peak amplitude of 4mm and dynamic loading from ±50N to ±10kN.

The main parts of the system are:-

  • Load Frame with Electromechanical Actuator
  • Triaxial Cell with accessories
  • Automatic Pressure system with Compressor & De-airing system
  • PC based Control system and Application Soft ware

Bender Element Testing System

HS 28.05 BE

HEICO Bender Element Test Set up system comprises of

  • Triaxial Cell with bender element for sample size 50 mm diameter (optional 75mm & 100mm)
  • Dual channel digital oscilloscope
  • Function Generator
  • Amplifier for the wave form.

Triaxial Cell

HS 28.05 BE

Complete with adopters and piezoelectric sensor. Accomodates samples size of 50 mm diameter (optional 75mm & 100mm) with L:d ratio as 2:1. Confining pressure 1 MPa.

Cell is complete with Rubber Sheaths (Pack of 10) Porous Stones with central bore of 25 mm, sheath stretcher and Ó’rings (pack of 6).

Dual Channel Digital Oscilloscope

HI 28.05

It is a Dual Channel high performance digital oscilloscope.

Dual analogue Channels

5.6 inch and 64k TFT LCD make the waveform display more clear and vivid.

Abudant trigger types, edge, pulse width, video, slope, alternate and duration.
Unique wave form record and display.

Dual Channel Function Generator

HI 28.10

Dual channel wave form generators adopt direct digital synthesis technology, which enables to generate stable high precision pure and low distribution signals.

Main feature are :-

  • Adopts advance DDS technology, dual channel output, 100 MSa/s sampling rate, 14 bit vertical resolution.
  • Output 5 standard wave forms.
  • Standard configuration interfaces, USB device and USB host.
  • Powerful arbitary waveform editing software. Company loaded.

Amplifier

HI 28.20

The wave is travelling from the emitter piezo sensor to the receiver piezo sensor and is travelling through a comparatively loose medium the signal received is very week. To have a better representative wave form on the oscilloscope screen this amplifier is used between the receiver piezo sensor and the oscilloscope.

Note : Confining Pressure And Back Pressuer Units Are Not Part Of The Supply And Same Has To Be Procured Separately Or Provided By Customer For Applying Cell Pressusre.